1. Sharon Park
Did not seem very crowded, easy parking with short walking distance, and 1-2 different spots for 10 people, and a few more if we wanted to do smaller groups too. Very photogenic and more refined looking.
2. Twin Pines Park
https://goo.gl/maps/mVDutEr2JeZU4gqN8
A few more people were present but not super crowded. A bit more outdoor/rugged looking but looks like it could be better for more spots that accommodate the entire group.
3. Central Park / Japanese Garden
https://goo.gl/maps/2tLvanS5o4qGWB338
As you mentioned this was quite crowded (most crowded of all options presented). The Japanese Garden itself may be tough for a group of 10, but there are a few areas in the surrounding vicinity that would be suitable. This had the furthest walking distance compared to the previous two, from underneath the tennis courts.
4. Sea Cloud Park
https://goo.gl/maps/2tLvanS5o4qGWB338
Not very crowded at all with parking but a further walk. Approx 300m to one or two good spots for the entire group along the pathway and towards the back of the park.
